3 files changed, 3 insertions, 46 deletions
diff --git a/dom/media/platforms/PDMFactory.cpp b/dom/media/platforms/PDMFactory.cpp
index a72d910f5..c1e58fdc2 100644
--- a/dom/media/platforms/PDMFactory.cpp
+++ b/dom/media/platforms/PDMFactory.cpp
@@ -47,10 +47,6 @@
 #include "MP4Decoder.h"
 #include "mozilla/dom/RemoteVideoDecoder.h"
 
-#ifdef XP_WIN
-#include "mozilla/WindowsVersion.h"
-#endif
-
 #include "mp4_demuxer/H264.h"
 
 namespace mozilla {
@@ -367,16 +363,7 @@ PDMFactory::CreatePDMs()
   }
 #endif
 #ifdef XP_WIN
-  if (MediaPrefs::PDMWMFEnabled() && IsVistaOrLater() && !IsWin7AndPre2000Compatible()) {
-    // *Only* use WMF on Vista and later, as if Firefox is run in Windows 95
-    // compatibility mode on Windows 7 (it does happen!) we may crash trying
-    // to startup WMF. So we need to detect the OS version here, as in
-    // compatibility mode IsVistaOrLater() and friends behave as if we're on
-    // the emulated version of Windows. See bug 1279171.
-    // Additionally, we don't want to start the RemoteDecoderModule if we
-    // expect it's not going to work (i.e. on Windows older than Vista).
-    // IsWin7AndPre2000Compatible() uses GetVersionEx as the user specified OS version can
-    // be reflected when compatibility mode is in effect.
+  if (MediaPrefs::PDMWMFEnabled()) {
     m = new WMFDecoderModule();
     RefPtr<PlatformDecoderModule> remote = new dom::RemoteDecoderModule(m);
     StartupPDM(remote);
diff --git a/dom/media/platforms/wmf/WMF.h b/dom/media/platforms/wmf/WMF.h
index 5ede0d361..6988ef083 100644
--- a/dom/media/platforms/wmf/WMF.h
+++ b/dom/media/platforms/wmf/WMF.h
@@ -7,18 +7,6 @@
 #ifndef WMF_H_
 #define WMF_H_
 
-#if WINVER < _WIN32_WINNT_WIN7
-#error \
-You must include WMF.h before including mozilla headers, \
-otherwise mozconfig.h will be included \
-and that sets WINVER to WinXP, \
-which makes Windows Media Foundation unavailable.
-#endif
-
-#pragma push_macro("WINVER")
-#undef WINVER
-#define WINVER _WIN32_WINNT_WIN7
-
 #include <windows.h>
 #include <mfapi.h>
 #include <mfidl.h>
@@ -35,7 +23,7 @@ which makes Windows Media Foundation unavailable.
 #include <codecapi.h>
 
 // The Windows headers helpfully declare min and max macros, which don't
-// compile in the prescence of std::min and std::max and unified builds.
+// compile in the presence of std::min and std::max and unified builds.
 // So undef them here.
 #ifdef min
 #undef min
@@ -97,8 +85,4 @@ HRESULT MFCreateDXGISurfaceBuffer(REFIID riid,
 } // end namespace wmf
 } // end namespace mozilla
 
-
-
-#pragma pop_macro("WINVER")
-
 #endif
diff --git a/dom/media/platforms/wmf/WMFUtils.cpp b/dom/media/platforms/wmf/WMFUtils.cpp
index 8aec8a8af..055012d0f 100644
--- a/dom/media/platforms/wmf/WMFUtils.cpp
+++ b/dom/media/platforms/wmf/WMFUtils.cpp
@@ -205,31 +205,17 @@ LoadDLLs()
 HRESULT
 MFStartup()
 {
-  if (!IsVistaOrLater() || IsWin7AndPre2000Compatible()) {
-    // *Only* use WMF on Vista and later, as if Firefox is run in Windows 95
-    // compatibility mode on Windows 7 (it does happen!) we may crash trying
-    // to startup WMF. So we need to detect the OS version here, as in
-    // compatibility mode IsVistaOrLater() and friends behave as if we're on
-    // the emulated version of Windows. See bug 1279171.
-    // Using GetVersionEx API which takes compatibility mode into account.
-    return E_FAIL;
-  }
-
   HRESULT hr = LoadDLLs();
   if (FAILED(hr)) {
     return hr;
   }
 
-  const int MF_VISTA_VERSION = (0x0001 << 16 | MF_API_VERSION);
   const int MF_WIN7_VERSION = (0x0002 << 16 | MF_API_VERSION);
 
   // decltype is unusable for functions having default parameters
   DECL_FUNCTION_PTR(MFStartup, ULONG, DWORD);
   ENSURE_FUNCTION_PTR_(MFStartup, Mfplat.dll)
-  if (!IsWin7OrLater())
-    return MFStartupPtr(MF_VISTA_VERSION, MFSTARTUP_FULL);
-  else
-    return MFStartupPtr(MF_WIN7_VERSION, MFSTARTUP_FULL);
+  return MFStartupPtr(MF_WIN7_VERSION, MFSTARTUP_FULL);
 }
 
 HRESULT